Martha drives from Jefferson to Holden, a distance of $250$ miles. She then travels on to Paxton, which is $50$ miles from Holden. If it takes her $5$ hours to complete the entire trip, how fast was she traveling if she was traveling at a constant rate?

The correct option is C $60\text{mi per h}$
Total distance traveled by Martha = distance between Jefferson to Holden $+$ distance between Paxton to Holden $=250+50=300mi.$
Total time taken by Martha to complete the trip is $5h.$
We are asked to calculate the speed at which Martha drove. Speed can be calculated by finding the unit rate.
$\text{Unit rate}=\frac{\text{total distance traveled}}{\text{time taken}}=\frac{300}{5}=60\text{mi per h}$